JP2005087976A - Production method and apparatus for rubber crumb by grinding - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for efficiently manufacturing powdered rubber from waste tire with a simple process, and its apparatus. <P>SOLUTION: In the method and apparatus, a rubber material such as tire is brought into contact with a rotating grinding means to continuously manufacture finely powdered rubber while preventing the rubber material from being softened by heating followed by grinding. According to the invention, the tire is not required for cutting or chipping. The invention dispenses with the repetition of kneading-separation for separating rubber from steel cord or cord, thereby efficiently manufacturing rubber crumb with low input energy. The invention obtains effects of obtaining fine rubber powder with uniform grain size and shape and dispensing with a sieving process. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method and apparatus for producing rubber powder by grinding, and more particularly, using a rubber material, for example, waste rubber material discharged in the course of production of waste tires, rubber products, etc. The technology for producing the powdered rubber, specifically, scraping the rubber from the rubber material by bringing the rubber material such as waste tires into contact with grinding means such as a rotating endless polishing cloth. In particular, the present invention relates to a method and an apparatus for producing powdered rubber. In the technical field of recycling and recycling of waste tires and the like, which is said to be about 100 million a year and a total weight of about 1 million tons, for example, the present invention makes it possible to reduce waste tires and the like by simple means at low cost. A new processing method and apparatus for rubber materials, which can be converted into a reusable powdered rubber (fine rubber powder), recycled rubber components contained in waste tires, etc., and recycled Providing new waste tire processing technology that can solve problems such as generation of dioxins caused by incineration of waste tires and contamination of surrounding environment caused by field processing, etc. Useful as a thing.

  Generally, among rubber products, about 90% of waste tires that discharge about 1 million tons per year are recycled in some form. The current recycling of waste tires is about 50% thermal recycling for burning tires and using it as fuel (thermal energy), about 20% for recycling as renewal tires, and materials that can be reused as rubber by grinding the tires, etc. Recycling is about 20%. As described above, most of the recycling of waste tires is thermal recycling used as fuel, and from the standpoint of resource protection and environmental conservation, development of technology for material recycling that reuses as rubber is anxious.

  Current material recycling of waste tires starts with cutting the tires into chips. The chips are mechanically forcibly kneaded to separate steel wires and fibers from the waste tire, and then rubber powder and steels are individually recovered using means such as magnetic separation and wind separation. However, in order to completely separate and collect only the rubber powder, this kneading-separation process must be repeated several times. In addition, waste rubber discharged in other rubber product manufacturing processes and the like is also recovered by granulating the rubber by the forced mixed treatment in the same manner. Examples of these reuse methods include a method in which rubber particles are used as a road pavement material, a paste material is added to rubber particles, agitated and mixed, and then molded into a rubber mat.

  Furthermore, the rubber particles can be crushed into fine particles by forcibly mixing them again. Thereafter, the rubber powder is desulfurized in steam under high temperature and high pressure and processed into a recycled rubber, which is used as a tire raw material or molded into a hose or a rubber plate. Recently, rubber powder is added to resin powder to form a plastic part having elasticity. As described above, in order to reinvigorate waste tires and waste rubber as recycled rubber, it is fundamental to produce rubber powder first.

  Conventionally, many methods for producing and recycling rubber powder from waste tires and the like have been proposed. For example, a separating and sorting machine for pulverized tires (Patent Document 1) that enables 100% recycling of waste tires, Waste tire recycling method that enables 100% recycling of each constituent material of waste tire (Patent Document 2), Waste tire recycling method that pulverizes or pulverizes the waste tire and recycles it (Patent Document 3) A waste tire grinding method and apparatus (Patent Document 4) have been proposed.

  However, the conventional method still has many problems to be solved in terms of practical use. For example, in many waste tires currently discarded, steel wires and cords are mixed in the tire. Since rubber and steel wire have significantly different characteristics of mechanical cutting, it is technically necessary to select the material and shape of the blade appropriately for efficient cutting and chipping of waste tires. With difficulty. Further, in order to completely separate rubber and steel or cords, it is necessary to repeat the kneading-separation process in many stages, and the energy required for these separations is enormous. This increases the cost of rubber powder production, which is a major factor that hinders recycling of rubber recycling. Furthermore, in the desulfurization process from rubber powder, the finer the rubber powder, the more efficient the desulfurization. Therefore, in order to enable the reuse of rubber, a fine rubber powder is desired. There is a limit to the refinement of rubber powder. In addition, as a method for obtaining fine particles, there is a method in which waste tires are cooled with liquid nitrogen and crushed after freeze embrittlement. However, this method is not a problem in terms of practical use in consideration of the cost of liquid nitrogen. In this technical field, there has been a strong demand to develop a new processing technology that enables waste tires and the like to be converted into refined and reusable fine rubber powder.

JP 2003-220351 A JP 2003-220349 A JP 2002-144241 A JP 2000-317335 A

Under such circumstances, the present inventors have been able to solve environmental problems in view of the above-mentioned conventional technology, and have been refined from rubber materials such as waste tires in an efficient and simple process. As a result of intensive research aimed at developing a method and apparatus capable of recovering rubber-like rubber, it is possible to obtain a powder by using a method in which a rubber material is brought into contact with an endless polishing cloth rotating at a constant speed. The inventors have found that rubber (fine rubber powder) can be continuously produced, and have completed the present invention.
An object of the present invention is to provide a method and an apparatus for producing a fine powdered rubber from a waste tire by a method that does not require a cutting step such as chipping and a repeating step of kneading and sorting, for example. To do. Furthermore, the present invention provides a novel fine rubber powder production method that makes it possible to produce fine rubber powder with significantly improved quality such as refinement and homogenization compared to rubber powder produced by a conventional method. And an apparatus for the same.

The present invention for solving the above-described problems comprises the following technical means.
(1) A method for producing a finely divided powder rubber from a rubber material such as a tire, wherein the rubber material is brought into contact with a rotating grinding means while preventing softening of the rubber product due to heat generated by grinding. A method for producing powdered rubber, comprising producing powdered rubber continuously.
(2) The method according to (1), wherein a portion of the tread portion and / or sidewall portion of the tire that does not include a metal material is brought into contact with a rotating grinding means.
(3) The method according to (1), wherein the grinding means is an endless type grinding cloth, a steel belt having irregularities on the surface, or a steel wire.
(4) The method according to (1), wherein the grinding means is of vitrified or resin bond wheel type.
(5) The method according to (1), wherein the grinding means is an abrasive cloth in which refractory particles are adhered on a cloth.
(6) An apparatus for continuously producing powdered rubber while preventing a softening of rubber due to heat generated by polishing by contacting a portion not including a metal material in a tread portion and / or a sidewall portion of a tire with a polishing means. A tire fixing / rotating device having a gripping tool for fixing the tire at a bead portion thereof and being rotatable, a grinding means, a tire tread installed in the tire fixing / rotating device, and / or An apparatus for producing powdered rubber, comprising: a notch driving device that enables the grinding means to move so that the sidewall and the grinding means can contact each other; and a cooling means for the grinding means.
(7) A cutting drive device in which the grinding means is composed of an endless belt provided between the rollers, and the grinding surface of the endless belt installed on the roller adjacent to the tire can be rotated and moved around the other roller as a central axis. The device according to (6), wherein the contact between the grinding surface and the tire can be changed.
(8) The apparatus according to (6), wherein the tire is ground, a cover is provided at a portion where the powdered rubber is generated, and a device for collecting the powdered rubber by a suction means is provided.
(9) The apparatus according to (6), wherein the grinding means is an endless type polishing cloth, a steel belt having irregularities on the surface, or a steel wire.
(10) The apparatus according to (6), wherein the grinding means is of a vitrified or resin bond wheel type.
(11) The apparatus according to (6), wherein a cooling unit is provided to prevent the temperature of the grinding unit from rising due to frictional heat generated during grinding.

Next, the present invention will be described in more detail.
The present invention relates to a method and apparatus for producing fine rubber powder from a rubber material, for example, typically a waste tire, and rotates while preventing softening of the rubber material due to heat generated by grinding. A fine rubber powder is continuously produced by bringing a rubber material into contact with a grinding means. The present inventors have made rubber materials such as waste tires into powdered rubber, and while researching technologies for recycling and recycling, until now, generally, by grinding the rubber materials, When trying to produce powdered rubber, the temperature of the rubber material rises due to frictional heat generated in the grinding process, and the rubber material softens, so it is considered that fine powder cannot be produced continuously for a long time. The present invention has been completed on the occasion of obtaining new knowledge capable of overcoming the common general technical knowledge.

  That is, when a rubber material such as a tire is subjected to a grinding process, frictional heat is generated along with the process. As a result of a detailed study by the present inventors, (1) rubber is a heat that is about one-third that of wood. Because it has conductivity, frictional heat does not conduct to the inside of a product such as a tire. (2) Therefore, in grinding, means for suppressing an increase in the temperature of the grinding means such as an endless type grinding cloth. (3) Thereby, it is possible to avoid an increase in the temperature of the tire grinding surface due to grinding, and that the grinding efficiency does not decrease due to the softening of rubber even if it is continuously treated for a long time. I understood.

Next, the manufacturing method and apparatus for powdered rubber (fine rubber powder) by grinding according to the present invention will be specifically described with reference to a waste tire.
FIG. 1 shows a cross-sectional view of a typical tire. As shown in the drawing, the tire includes a tread portion including a steel wire, a bead portion including a bead wire, and a sidewall portion. In the present invention, powdered rubber is produced by grinding the portion of the tread portion that does not include the steel wire or the sidewall portion.

  FIG. 2 shows an example of a basic configuration for producing powdered rubber by bringing a grinding cloth into contact with the tread portion of the waste tire of the present invention. The waste tire 1 placed in the horizontal direction is gripped by the tire bead portion with a pair of upper and lower clamps 2 and fixed. The fixed waste tire rotates slowly in the horizontal direction together with the clamp. Surprisingly, it is found that the rubber surface of the waste tire can be extremely easily ground and fine rubber powder can be produced by pressing a grinding means such as an endless type grinding cloth 3 against the rotating waste tire. It was.

  As described above, since rubber has a low thermal conductivity, frictional heat generated during grinding is not conducted to the inside of the tire. Therefore, the frictional heat generated during grinding is mainly consumed for increasing the temperature of the grinding means, for example, the endless type grinding cloth itself. Examples of the cooling means of the grinding means include a method of making the grinding cloth longer than usual, a method of installing a powder rubber suction device, and a method of installing a cooling device. If these methods are used, the grinding cloth is cooled during rotation, the temperature rise of the grinding means is suppressed, the temperature rise of the tire grinding surface due to grinding is avoided, and the rubber is softened even after continuous treatment for a long time. There is no reduction in grinding efficiency.

  In the present invention, the cooling means of the grinding means may be provided with a specially prepared cooling device. For example, if a device for collecting powdered rubber produced by grinding is provided, the grinding is performed along with the suction. Since the outside air circulating around the means serves as a cooling means, it is not necessary to provide a cooling device in practice. Thus, in the present invention, as a method for suppressing the temperature rise of the grinding means, preferably, as described above, a method of lengthening the grinding cloth to such an extent that the temperature rise is avoided is exemplified. The invention is not limited to these. In addition, as an endless type polishing cloth, a resin bond type in which refractory particles such as SiC are bonded with a resin is used. By controlling the temperature rise by the cooling means, the durability of the polishing cloth is improved. Moreover, it can be ground efficiently and there is no possibility that refractory particles are mixed in the powdered rubber.

In the present invention, the grinding means is preferably exemplified by a grinding cloth, but is not limited thereto. For example, a steel belt, steel wire or the like having a sharp unevenness on the surface may be used. The same effect can be obtained, and for example, the same effect can be obtained with wheel type grinding means such as vitrified and resin bond. In the present invention, any means equivalent to these can be used similarly. .
In the basic configuration diagram of the example shown in FIG. 2, only the tread portion is ground, but the sidewall portion can also be ground in the same manner. Can be adjusted.

The apparatus and method of the present invention will now be described in detail.
FIG. 3 is a side view of an apparatus according to a preferred embodiment of the apparatus of the present invention, and FIG. 4 is a plan view of the apparatus. First, the tire 1 is gripped by the chucking unit 4 attached on the chucking table 5. For example, as shown in FIG. 4, the chucking unit 4 includes a pair of upper and lower clamps 2 that can grasp the tire at a plurality of locations, and can grip the tire 1 by manual tightening with a screw or hydraulic pressure. The chucking table 5 rotates the tire 1 by being rotated by the tire rotating device 6. The endless type polishing cloth 3 is moved between the pair of rollers 9 and 10 by a motor 8 attached to the grinding unit table 7. The grinding unit table 7 is attached to a table support 11. The table support 11 is directly connected to the incision driving device 12, and the incision driving device 12 can be rotated about 45 degrees in the horizontal direction by hydraulic pressure as shown in FIG.

  The apparatus for producing powdered rubber by grinding according to the present invention is configured as described above, but the specific configuration of each means can be arbitrarily designed. Next, the operation of processing tires and producing powdered rubber using this apparatus will be described. First, the grinding unit is operated by the cutting drive device, placed at the position of A shown in FIG. 5, the tire 1 is placed on the chucking table 5, and the tire 1 is gripped by the chucking unit 4. Subsequently, after rotating the tire 1 shown in FIG. 5 in the clockwise direction by the tire rotating device 6, the endless type grinding cloth is rotated in the clockwise direction. Therefore, the incision driving device is fed in the direction from A to B shown in FIG. 5, the endless type grinding cloth that makes a circular motion is brought into contact with the tire 1, and grinding of the tire is started. The amount of cutting is adjusted by adjusting the moving distance of the cutting drive device, cutting is performed so as not to touch the steel wire in the tire, the tire is ground, and a refined rubber powder is produced.

  In the present invention, the rotational speed of the tire, the peripheral speed of the grinding cloth, and the moving speed of the cutting drive device are related to each other and affect the particle size, properties, production speed, etc. of the produced powdery rubber. This value is set within a predetermined range according to the properties of the desired powdery rubber, the physical properties of the tire as the raw material, and the like. The apparatus for producing powdered rubber by grinding according to the present invention can be provided with a means for collecting powdered rubber. 3 and 4, the rubber powder recovery device 15 is connected to a rubber powder recovery cover 13 and a rubber powder recovery hose 14 provided in the powder rubber generation unit. The rubber powder recovery device itself is composed of an exhaust device and a filter. It is made up. In the rubber powder collection cover 13, the powdered rubber produced by grinding is collected by suction, and at that time, the endless type grinding cloth comes into contact with the outside air and is cooled. By this cooling, the frictional heat generated during tire grinding can be removed to such an extent that it can be practically used.

  The present invention relates to a method and apparatus for producing fine rubber powder directly from waste tire, and according to the present invention, (1) it is not necessary to cut and chip the tire as in the conventional method, (2) There is no need to repeat kneading and sorting to separate rubber and steel wire or cord. (3) Efficient production of rubber powder with low input energy. (4) Fine particles with uniform particle size and shape. Fine rubber powder is obtained, and the sieving step is not required. (5) The fine rubber powder that can be suitably supplied to the desulfurization step can be produced.

  EXAMPLES Next, although this invention is demonstrated concretely based on an Example, this invention is not limited at all by the following Examples.

  A passenger car tire having a diameter of 620 mm and a width of about 160 mm was used and fastened on the chucking table by a chucking unit, and then the chucking table was rotated at 0.26 rpm. Further, a pair of opposed endless polishing cloths were brought into contact with the tread portion of the rotating tire. The contact pressure was about 6 kg, and the peripheral speed of the endless abrasive cloth was 1200 m / min. The abrasive cloth used was a commercially available endless paper having a circumference of 1800 mm and a width of 180 mm prepared by kneading corundum particles with an organic adhesive and spreading on an endless cloth. It was. As the rubber powder collecting device, a suction device with a suction amount of 2 kl / min and a filter were used and rubber powder was collected by this collecting device.

  Under the above conditions, the powdered rubber production apparatus described in the examples was continuously operated to produce rubber having a particle size of 0.5 mm or less at a rate of about 0.48 kg / min. In FIG. 6, the observation photograph by the scanning electron microscope of the obtained rubber powder is shown. As shown in the figure, the particle size was 0.5 mm at the maximum, almost granular, and the particle size was well-organized. A finer rubber powder can be obtained by using a finer, endless type polishing cloth. In the production of rubber powder from conventional waste tires, as in the present invention, there has been no example in which a powdery rubber of 0.5 mm or less can be produced efficiently and quickly in a single step with a simple apparatus. As described above, it was possible to produce a rubber powder that was extremely simple and superior in quality as compared with the prior art.

  As described above in detail, the present invention relates to a method and apparatus for producing rubber powder by grinding, and according to the present invention, the present invention can be refined more efficiently than rubber materials such as waste tires by simple means and methods. Powdered rubber can be produced continuously. In the present invention, for example, a fine powdered rubber can be continuously produced in a single step without the need for a cutting step such as chip formation in the conventional method and a repeating step of kneading and sorting. The powdered rubber produced according to the present invention has remarkably improved quality such as miniaturization and homogenization compared to conventional products, and for example, it is possible to efficiently perform desulfurization treatment. The present invention is useful as, for example, providing new technology that enables recycling, recycling, and recycling of rubber using waste tires and realizing the creation of such new industries.

A tire sectional view is shown. The enlarged view of a tire grinding part is shown. The tire grinding device side view is shown. The tire grinding device top view is shown. The grinding cutting block diagram is shown. The observation photograph by the scanning electron microscope of the rubber powder obtained by this invention is shown.

Explanation of symbols

(Reference numerals of FIGS. 2, 3, 4 and 5)
1: Tire 2: Clamp 3: Endless type polishing cloth 4: Chucking unit 5: Chucking table 6: Tire rotating device 7: Grinding unit table 8: Motor 9, 10: Roller 11: Table support 12: Cutting drive device 13: Rubber powder collection cover 14: Rubber powder collection hose 15: Rubber powder collection device 16: Base

Claims (11)

  A method for producing a fine powdered rubber from a rubber material such as a tire, wherein the rubber material is brought into contact with a rotating grinding means to prevent softening of the rubber product due to heat generated by grinding. A process for producing a powdery rubber, characterized in that is produced continuously.   2. The method according to claim 1, wherein a portion of the tread portion and / or sidewall portion of the tire that does not include a metal material is brought into contact with a rotating grinding means.   The method according to claim 1, wherein the grinding means is an endless type grinding cloth, a steel belt having irregularities on the surface, or a steel wire.   The method according to claim 1, wherein the grinding means is of the vitrified or resin bond wheel type.   The method according to claim 1, wherein the grinding means is an abrasive cloth having refractory particles adhered on the cloth.   An apparatus for continuously producing powdered rubber while contacting a portion not including a metal material in a tread portion and / or a sidewall portion of a tire with a polishing means to prevent softening of the rubber due to heat generated by polishing. A tire fixing / rotating device having a gripping tool for fixing the tire at a bead portion thereof, which is rotatable, a grinding means, a tire tread and / or a sidewall installed in the tire fixing / rotating device; An apparatus for producing powdered rubber, comprising: a notch driving device capable of moving the grinding means so as to be in contact with the grinding means; and a cooling means for the grinding means.   The grinding means is composed of an endless belt provided between the rollers, and the grinding surface of the endless belt installed on the roller adjacent to the tire can be rotated and moved about the other roller as a central axis by the cutting drive device. The device according to claim 6, wherein the contact between the grinding surface and the tire can be changed.   The apparatus of Claim 6 which provided the apparatus which grinds a tire, provided the cover in the part which powdered rubber generate | occur | produces, and collect | recovered powdered rubber with a suction means.   The apparatus according to claim 6, wherein the grinding means is an endless type polishing cloth, a steel belt having irregularities on the surface, or a steel wire.   The apparatus according to claim 6, wherein the grinding means is of the vitrified or resin bond wheel type.   The apparatus according to claim 6, further comprising cooling means for preventing the temperature of the grinding means from being increased by frictional heat generated during grinding.